This month is "Will-Aid", where for a donation to charity you can have a will drawn up. The donation is purely up to you but what would be a reasonable amount.
Yes, its something I need to do and I may do in the next month, thanks for adding this question..
I see from the Will-Aid website they quoted the following which looks fair "the suggested donation level is just �75 for a single Will, �110 for a pair of 'mirror' Wills and �40 for a codicil to an existing Will".
I would say �75 is fair to pay for the Will to be prepared.